Referring to FIG. 1, a conventional fan structure 10 typically comprises a base 11, a shaft tube 12 disposed on the base 11, a bearing 13 disposed within the shaft tube 12 and a rotor 14. The rotor 14 at least comprises a pivot 14a disposed into the bearing 13 and a fan wheel 14b. When the fan structure 10 is assembled via above procedure, it needs an adhesive or screws to fix all components thereby resulting consumptions of manpower and time because of the assembled procedure is too complicated.